Phenoxyethanamines are known materials. They are useful, when at least partially neutralized, to produce thermosetting resins having extended pot life and a fast cure rate, such as described in U.S. Pat. No. 4,353,819, as an example. They have shown promise as surfactants as noted in Chemical Abstracts 99(22):177867h. Phenoxyethanamines are used to make froth-flotation collectors according to Chemical Abstracts 106(6): 36486j of European Patent Application 174,866, and in the production of coal flotation conditioners as described in Chemical Abstracts 103(18): 144675s of Indian patent document 154,360.
Unfortunately, phenoxyethanamines are difficult to make. While making the amide intermediates from reacting phenols with 2-oxazolines is known, converting them to the amines has proved hard. The sodium hydroxide method tends to have undesirably long reaction times. It was discovered herein that using hydrochloric acid or sulfuric acid to perform the hydrolysis gives poor selectivity to the desired phenoxyethanamine. Thus, it would be advantageous if a new route to these valuable materials were discovered.
J. A. Frump, in "Oxazolines. Their Preparation, Reactions, and Applications," Chemical Reviews, Vol. 71, No. 5, 1971, pp. 483-499 in his survey teaches the reaction of 2-phenyl-2-oxazoline and phenol over 7 hours to give N-[1-(2-phenoxyethyl)]benzamide. Other reactions with similar materials are also noted. Chemical Abstracts 99(22): 177867h, mentioned above, indicates that amines with the structure p--C.sub.9 H.sub.19 C.sub.6 H.sub.4 O(CH.sub.2 CH.sub.2 O).sub.n CH.sub.2 CH.sub.2 NHR, where R is hydrogen or CO.sub.2 R.sup.1, R.sup.1 being an alkyl having 1 to 5 carbon atoms, and n is 0 to 10, are prepared by treating p--C.sub.9 H.sub.19 C.sub.6 H.sub.4 O(CH.sub.2 CH.sub.2 O).sub.n H with CH.sub.2 .dbd.CHCONHR, where R is defined as above, in the presence of polymerization inhibitors and then converting the amide intermediate to the amine by a Hofmann rearrangement.
An improved vehicle for the formulation of baking enamels may be obtained by reacting an oxazoline with phenol according to U.S. Pat. No. 3,654,229. Materials such as 2-[1,1-bis(hydroxymethyl)] oxazoline diester and 2-[1,1-bis(hydroxymethyl)ethyl]-4-ethyl-4-propionoxymethyl-2-oxazoline were reacted with phenol. The products were dissolved in methanol to form the vehicles.
U.S. Pat. No. 4,596,884 describes an improved process for the preparation of 5-ethyl-4-(2-phenoxyethyl)-1,2,4-triazolone, a useful intermediate in the synthesis of antidepressant 1,2,4-triazolones. One of the steps in the process involves the reaction of phenol and 2-ethyl-2-oxazoline to give an intermediate compound N-(2-phenoxyethyl)propionamide. The reactions of cyclic imidic esters (2-oxazolines) with phenols and other materials proceed with ring cleavage and formation of 2- or 3-substituted N-alkylamide derivatives, and less frequently of 2-aminoethyl or 3-aminopropyl esters of carboxylic acids, as taught by W. Seeliger, et al., "Recent Syntheses and Reactions of Cyclic Imidic Esters," Angew. Chem. internat. Edit., Vol. 5, No. 10, 1966, pp. 875-888.
U.S. Pat. No. 4,195,154 describes the preparation of 2-amido- or 2-amino-alkyl ethers of polyhydric polyphenols by reacting a 2-oxazoline with a polyhydric polyphenol in the presence of certain metal salt catalysts, e.g. zinc acetate. The resulting materials appear to have use as epoxy curing agents and have insecticidal, fungicidal and bacteriocidal activity.
Of lesser importance and relating to the background of 2-oxazolines, is the article "Cyclic Imino Ethers, Polymerization" appearing in Encycl. Polym. Sci. Technol., Suppl. 1, 1976, pp. 220-237. Somewhat similar reactions to those described above are seen in U.S. Pat. No. 4,086,273 which reacts n-octylmercaptan with 2-ethyl-2-oxazoline in the presence of a catalytic amount of hydrated cadmium chloride at a temperature of approximately 200.degree. C. for one hour. The resulting .beta.-aminoethyl sulfides are known to have a variety of uses.